Process for making metal products



Sept. 13, 1 938. J. M. MERLE 2,129,702

PROCESS FOR MAKING METAL PRODUCTS Filed May 5, 1954 2 SheetsSheet 1 gawk.Joscyab M. Marie;

Sept. 13, 1938. J. M. MERLE PROCESS FOR MAKING METAL PRODUCTS Filed May5, 1934 2 Sheets-Sheet 2 de M. w J

Patented Sept. 13, 1938 mocsss ron mama METAL monuo'rs Jmpil. M. Merle,Tarentum, Pa. Application May 5, 1934, Serial No. 724,188

Claims.

The present invention relates to a method of manufacturing cutting toolsand other metal products from molten tool steel or other metals oralloys.

With the exception of those metal products made from powdered metalssintered under heat and pressure, such products are customarily madefrom molten metal poured into a metal mold, sand mold or rotary mold, orare forced under mechanical or air pressure intoa mold or die. In everycase of a metal product made from molten metal as above indicated, suchmolten metal reaches the mold or die in a liquid state and, while insidesuch mold or die, passes from the liquid state to the solid state, thischange of physical condition involving well known phenomena which varysomewhat depending upon the specific metal or alloy involved.

This common method of production of metal products has a determininginfluence upon the physical and other properties-and characteristics ofall commercial metal products either in their cast condition or in theirworked condition resulting from forging, roiling, pressing, extruding ormechanical forming, as well as in their heat treated conditiomthefinished product retaining some of the characteristics of the crystalsformed and propagated through the molten metal.

An object of the present invention is to avoid the conditions which takeplace when molten metal passes from the liquid to the solid state in amold or die since I have observed that by forcing molten high speedsteel or other steel into molds or dies not in the liquid state but in afine atomized spray of undercooled but still plastic particles propelledat a relatively high speed, such particles would impact together whencontacting with the mold wall or with a section of the prodnot alreadyformed. The tools so formed disclose a different structure and difierentproperties than tools made of ingot steel of the same composition butwhich have been produced by pouring liquid steel into an ingot mold, theingot being subsequently hammered and/or rolled.

l have also observed that in steel or other metal products so made eachof the undercooled atomized particles solidifies spontaneously uponimpact while aggregating to other particles previously impacted therebyforming a metal product or increased density and cohesion, homogeneousin structure and free of the conditions occurring within an ingot when alarge mass of molten metal passes from the liquid to the solid state,namely, dendrites, segregation, pipe and heterogeneity, and further thatthe grain size of the metal product so formed may be controlled byregulating the size of the atomized particles.

Also I have observed that the same structure and conditions are obtainedby forcing the undercooled atomized particles not into a mold butthrough. a die, out of which the formed metal product is drawn orstripped at a rate corresponding to the amount of atomized metal forcedinto it, thereby forming metal products in bars, strips, sheets, orshapes in continuous lengths.

Furthermore, I have observed that steel and other metal products soformed have physical properties no longer comparable to the same metalas at present commercially cast, but better than the properties of thesome metal commercially worked by iorging, rolling, or extruding. Morespecifically, cutting tools formed by this method are much better andcan withstand a cutting speed two to three times as great as the cuttingspeed obtalnable with tools made of steel of the same composition as atpresent commercially produced.

In metal products so formed the latent heat of the molten metal iscompletely dissipatedbefore atomizing and each atomized particle isundercooled slightly below the ireezing point, so that a crystalnucleus, extending to a part of or entirely through the particle, hasbeen formed and upon colliding and impacting with other particles, themetal atoms can find satisfactory arrangements, thus giving a structurefree of internal stresses. Each particle also spontaneously crystallizesupon impact without iurther disturbance due to latent heat dissipationthrough the crystals formed, thus making metal products of a distinctiveand physically new structure, which is retained through subsequentmechanical working operations or heat treatment. This structure for allmetals and alloys is characterized by minute spheroid cells of identicalsize, free of dendritic needles, with impurities located at the grainboundaries, as well as supersaturated alloy components concentrated atthe grain boundaries and with precipitating components uniformlydistributed as minute particles throughout the product formed. Thereby ameta1 product is formed which is uniform in structure under anymagnification, more dense and stronger than similar metal products ofthe same composition, having the same strength, elongation, elasticlimit and reduction of area in every direction and will give anon-directional iracture. Furthermore, the metal products are notsubject to any chilling efiects from metal molds and are free fromdendrites, flow lines, segregation, pipes, shrinkage cavities, etc, andthey have the same chemical composition throughout the entire section orany part of the product. This special structure is retained afterforging, rolling, heat treatment and even after welding when using themetal product as a welding rod.

In the case of high speed steel, the hard carbide components aredisposed in a network around each martensitic crystal thereby impartingto each grain a cutting edge around its periphery and thus accountingfor the better cutting properties over steel of the same composition aspresent commercial products. The distribution of the carbides isentirely uniform, and, in the case of chromium stainless steel, the samestructural disposition accounts for better resistance to corrosion.

Molten substances such as molten glass or rocks so formed are also givena distinctly new structure and new properties.

I have also observed that cutting tools can be formed of a layer of highspeed steel made from impacted undercooled. atomized particles and alayer of strong and tough alloy steel made in the same manner ofimpacted undercooled particles, the two layers being perfectly bondedtogether by this method and beingstrong enough to withstand, withoutbreaking, increased cutting speeds.

Furthermore, finely powdered particles of tungsten, tantalum, titaniumor other metal carbides, either one kind or several kinds at the sametime, as well as finely powdered particles of diamond, can be dispersedthrough the atomized particles of high speed steel or other metal, thelatter forming a matrix around the hard carbide or diamond particleswhich impart to the tools very desirable cutting properties. Byundercooling the molten metal below the freezing point before atomizingand impacting the particles, 9. spongy metal product can be formed withvoids uniformly distributed, the size of the voids being controlled bythe regulated size of the atomized particles.

I have observed also that nickel, copper, zinc, cadmium, brass, etc. soformed into metal products have very desirable properties for theplating industry, as anodes so formed, on account of their homogeneousfine structure, will corrode uniformly in the plating bath, withoutleaving any deposit in the tank, thus eliminating the use of diaphragmsas at present used, and making a more uniform deposit on the-platedproduct, free of trapped gas pockets, which will last longer and lookbetter than the deposits as obtained from present commercial anodesi Thephysical conditions previously described under which the molten metal isforced into molds or dies or through dies, can be produced by variousmethods. Several methods are illustrated diagrammatically in theaccompanying drawings, it being understood that other methods ofundercooling, atomizing and propelling the molten metal can also producethe same results.

In order to more clearly understand the invention, particularly thetools and products, and the method of making them, it will now bedescribed with reference to the accompanying drawings, in which:

Figure 1 is a horizontal top view of a rotary atomizing disc and a partof a stationary circular receiving mold,

Fig. 2 is a vertical'sectional view through the rotary atomizer and moldof Fig. 1 and through the receptacle feeding molten metal to theatomizing disc,

Fig. 3 is a vertical sectional view of an inclined atomizing disc with adifferent mold which can be stationary or rotary, to receive theatomized particles in a spiral spray,

Fig. 4 is a cross sectional view of a product obtained in the machine ofFig. 3,

Fig. 5 is a vertical sectional view of the atomizing disc of Fig. 1showing the spraying of the atomized metal into a rotary mold for shapedFig. 6 is a cross section of a formed tool, made of two metal layers,

Fig, 7 is a cross section of a tool made of three layers of steel,

Fig. 8 is a vertical sectional view of a belt shaped undercooler andatomizer and showing a cross section of a water jacketed mold forcontinuous metal products,

Fig. 91s a cross section of the metal belt undercooler and atomizer ofFig. 8,

Fig, 10 is .a horizontal elevation of the belt atomizer and mold of Fig.8,

Fig. 11 is a vertical sectional view of two belt atomizers and a moldfor continuous bimetal products; and

Fig. 12 is a part sectional and side view of a modified type of machine,similar to Fig. 11 but for metal coatings.

The various parts of the machine can be described by detailing theoperation of the machine, and as to Figs. 1 and 2 it is as follows:

The molten metal I 4 in the receptacle l3 runs out through a series oforifices l5, whose number, size, and shape have an influence on thedegree of undercooling desired. This molten metal contacts with arotating disc I along a circumference line 2, Fig. 1, this part orsection of the disc having already a considerable peripheral speed whichprevents the molten metal from adhering to or burning the atomizing discwhich would probably take place if the metal contacted with the centerof the disc. The atomizing disc I is composed of two parts, an upperpart 6 and a lower part i spaced from each other to provide a space 8therebetween into which cooling fluid such as water may be fed. Thewater or other cooling fluid is fed to the receiving space 8 by the pipe9 disposed within shaft 9 on which the disc is mounted and runs out ofspace 8 through the space 9 in the shaft between the stationary waterpipe 9 and the center bore 9 of the shaft. The water flow will maintainthe atomizing disc at substantially a constant temperature by taking upthe heat imparted to the disc by the molten metal.

The atomizing disc I is journalled in ball bearing l0 and otherbearings, not shown, and is driven (at a high rotative speed) bysuitable means, not shown, associated with the shaft 9. The molten metalfalling on the revolving disc on the circular line 2 forms a film whichspreads out over the surface on the upper part 6 of the disc extendingfrom the line 2 to the periphery of the disc, and while in such filmstate the metal loses heat by contact with the cooled surface of thedisc and is thus undercooled. The thus undercooled metal film on leavingthe periphery of the disc breaks up into a fine spray of atomizedparticles which are propelled at a high speed in a direction preciselyat relative to the axis of rotation of the disc. The particles of metaltraveling as a spray and at high velocity enter the stationary circularmold I6 through a circular slit it! which is exactly in the path oftravel of the particles. These particles are solidified and united witheach other under impact in the mold and fill up the mold cavity 4.

In the form of construction shown in Figs. 1 and 2, the exact amount ofmolten metal sufficient to fill the mold cavity is poured into thereceptacle l3. When all the molten metal has been atomized and sprayed,the top part I 6 of the mold I6 is lifted from the bottom part II. Thecast product, which may be formed as an integral circular unit or in twoor more sections, three being shown in Fig. 1, by placing separatingpieces 5 in the mold, is stripped from the part I1. The casting or thesections may have a fin molded thereon corresponding to the feeding slitif excess metal has been poured, but since the slit is only a fewthousandths of an inch wide, the fin can easily be broken or cut awayand the sections may be straightened in straightening rolls, ifnecessary. The plates II and I! on the mold parts l6 and I! completelyclose the space in which the disc rotates, and no air is admitted whilethe molten metal is being poured. In this way the atomized particles,while being propelled at high velocity as a spray from the disc to themold cavity, are not subjected to possible oxidation, and preferably theair contained adjacent the disc is pumped out by means of pipe l9, sothat the undercooling, atomizing, and impacting are carried out in avacuum. If desired, hydrogen, a mixture of hydrogen and nitrogen,illuminating gas, or blue gas can be forced into the space adjacent thedisc and in the mold cavity, if such gases are beneficial to the metalbeing sprayed and cast.

The undercooling of the metal, the size of the atomized particles, andthe velocity at which the particles are propelled can be regulated atwill. The fiow of molten metal from the receptacle l3 depends on thenumber and cross sectional areas of orifices l5 and can be made of suchsize and number as to feed from to 500 lbs. or more of molten metal perminute. disc having an outside diameter of 12", the molten metal can bemade to drop on the circular line 2 on the upper part 6, which line mayvary from 2" to 10" in diameter. This varies the time during which thefilm of moving molten metal is in contact with the upper surface 6 ofthe disc I. The temperature of the surface 6 of the disc may beregulated by varying the flow of water through space 8, and can bemaintained at a low value or at a temperature of about 300 F. The speedof the rotary disc can vary in practice from 1,800 R. P. M. to 6,000 R.P. M., as the higher the speed the thinner the film of metal formed, andthe smaller the size of the particles of metal sprayed from the disc,the greater their velocity and impacting power.

With these regulations, the grain size of the metal product can becontrolled and products of increased density and increased strength overpresent commercial products can be produced. Furthermore, by reducingthe flow of molten metal from the receptacle and increasing the lengthof its travel over the surface of the disc, the metal is undercooled,that is, the metal is cooled to a temperature below its freezing pointand, the film breaks into particles already partly solid or entirelysolid, and these particles, due to their velocity, unite by impact witheach other into a solid but spongy metal product with uniform voidsbetween the particles.

If, for instance, the undercooled solid particles are not collided andimpacted together within a short distance after leaving the rotary discto form a solid product, but are allowed to travel a distance of severalfeet before impacting against the walls of the chamber, they will notimpact together but will be collected as powdered metallic particles.Depending on the speed used and the amount of undercooling, theseparticles may be .in Fig. 2, being made either in an airtight space orWhen using a rotary chamber or under a vacuum, or in a chamber filledwith a neutral gas, the granules or particles are not subject tooxidation; Furthermore, a special gas, such as ammonia gas, can be usedwhich will dissociate under the heat of the particles, and when usingsteel or another alloy capable of being nitrided, the granules orparticles will attain a hard nitrided surface which is useful in severalcommercial applications.

The apparatus shown permits the handling of 10 metals or alloys of lowmelting point, as well as metals or alloys of high melting point,byadapting the conditions of flow, undercooling and atomiz-jl. ing tosuit the various metals or alloys. It is further noted that practicallynone of the molten l5 metal is lost as by heads, pipes, or grates, whichhave to be cut oif from the solid product formed.

Fig. 3 shows a rotary atomizing disc as used in connection with a billetor slab mold, but in this instance, the disc instead of being set at 90to 20 the axis of the shaft rotating it, is set at an angle to theshaft, the amount of angularity depending upon the height of the billetor slab to be made in mold 20 and 2| whose cavity is in a plane at rightangles to the shaft. In this arrangement 25 the spray of metal onleaving the rotary disc I travels in a straight line, indicated by thearrows, exactly 90 to the axis of rotation of the shaft, and will buildup the section of the billet or slab by evenly distributing theparticles in a. spiral 3 path throughout the height or width of theproduct formed. The mold parts 20 and 2| are stationary or can berotated at low speed. The billets formed have good surfaces, are ofuniform structure, free of pipe shrinkage cavities, and are 35 ready forrolling. A vertical shaft is shown, but in view of the high velocityused, gravity has no effect on the molten metal poured'over the rotarydisc, and therefore the shaft of this disc can be in any position whichmay be more convenient 40 for the operation of the process.

Fig. 4 shows a section of a product or casting made by pouringsuccessively into receptacle l3 of Fig. 1, first one type of metal, forexample stainless steel 24, then another type of metal 25, 45

such as low carbon steel, then stainless steel 24 again, if desired, sothat a billet or slab is formed in the mold of Fig. 3 having a core 25of low carbon steel and faces 24 of stainless steel, the

layers being perfectly bonded together by the 5 velocity of impactwithout any impurities, slags,

or oxides at the junction of the various layers.

junction between the distinct metals or alloys is free of gases, oxides,and other impurities and the products may be rolled or forged withoutany rupture or separation at the junction of the distinct metals.

Fig. '5 shows the same rotary disc and pouring receptacle as Figs. 1 and2, but the atomized spray is received in mold 2'! and 28 which is alsorotated by means of pulley 32, the direction of rotation being the sameor the opposite to the direction of rotation of the rotary disc. Themold 21 and 28 has cavities each corresponding to the shape of theformed tools or other products, there being two or more of thesecavities to receive the spray from the rotary disc. When making cuttingtools of two layers of steel, first high speed steel of any of thecommercial compositions is poured into receptacle l3 and this steel isformed into a film, undercooled and atomized, and these particles whenreaching the mold cavities on account of the rotation of mold 21 and 28form a layer 35 parallel to the axis of rotation of the mold. Then atough alloy steel, such as chrome-nickel steel or chrome-vanadium steelis poured into receptacle l3 and also undercooled and atomized, and thissteel is sprayed into a layer 36 adhering to the layer 35 of high speedsteel until the tool cavities of the mold'are filled up. The secondsteel is poured in the receptacle before the high speed steel hasentirely drained out, so that particles of both kinds of steel areintermingled at the junction of one to the other through a thickness ofa few thousandths of an inch, thus making the two layers so inseparablybonded that they cannot be parted by any mechanical means. To receptaclel3 may be attached another receptacle 26, through which finely powderedmaterial such as diamond powder or pulverized metallic carbides can beintroduced at the same time that the high speed steel is poured, so thatthe pewdered material will be carried out on the film of molten metaland evenly dispersed into it. When the metal breaks into a spray, theatomized metal particles and the powdered carbides are both propelledtogether at the same speed and will impact and aggregate together in thelayer formed in the rotary die or mold. This provides the tool with hardparticles uniformly dispersed through a matrix of either high speedsteel or some other binding metal, such as cobalt, nickel, high strengthbronze, etc. Through receptacle 26 another molten metal can be poured,for example lead, and through receptacle l3 bronze can be poured, sothat an. increased amount of lead can be dispersed through the bronzebase metal as finely divided particles to improve the properties of thebronze for bearing purpose. Finely powdered graphite can be used for thesame purpose and dispersed through the base metal. The foregoingdescribes some of the products which can be produced by building them ofundercooled atomized particles instead of starting from a molten metalpoured into a mold.

Milling cutters, hobs, rock drills, core drills, rotary saws, and othertools can be formed in the same manner having a hard cutting steel alloyor abrasion resisting alloy on the outside surface, and a core of toughand strong steel or other metal inside. Furthermore, as in ordinary diecasting machines, inserts, of metallic or other suitable materials, canbe placed in the die to become a part of the casting after the metalparticles have been consolidated therein under impact.

Fig. 6 shows a forming tool, finished to grinding size, having a. layerof high speed steel 35 with or without carbides or diamond powderdispersed therein and a. layer of tough steel 36 for the support of thetool.

Fig. 7 shows a bar for twist drills, made of a central layer 31 of highspeed steel or other cutting material and two sectors 38 of a toughsteel which will render the drill unbreakable.

Figs. 8 to 10 show a band undercooler and atomizer, the band being madeof a steel or other metal ribbon similar to the band of a band saw or ofsome non-combustible material but preferably having a section as shownin Fig. 9. This band 42 runs over grooved pulleys 43 and 44 at highspeed by means of a driving grooved pulley 45 which is connected to amotor or to a belt drive by means of shaft 55. The molten metal ispoured into receptacle 39 whose nozzle contacts with the groove 51 ofthe band 42 at 4|. This receptacle 39 is supported over the frame 54 ofthe machine. A steady flow of molten metal is drawn through nozzle 56and is propelled in the groove 51 of the band 42. The film formed in theband is very thin and when the band turns over pulley 44 this film underits velocity breaks into a fine spray of undercooled metal particles andis propelled into mold 41, thus forming a solid metal product of anydesired section or shape depending upon the shape of the mold. This moldcan be water-jacketed by means of the jacket 48 with inlet 50 and outlet49 to maintain the mold at a constant temperature. A pair of rolls 52and 53 draws the solid bar 5| formed at a rate of speed depending on theweight of metal flowing per minute from nozzle 4| and of the section ofthe metal product formed. The velocity of the atomizing band can be madeto vary to correspond to the same peripheral speeds indicated for therotary disc of Figs. 1 and 2, thus producing the same underccoling andatomizing conditions and the same characteristics as indicated in theforegoing in metal products formed in continuous lengths. The band 42passes through a cooling liquid 46 in a depression 46' in the frame 54to maintain the'band at a constant temperature to receive a film ofmolten metal, thus maintaining constant conditions of operation. Withthis design, strips of sheet metal or other shapes of any thickness andwidth can be formed. As indicated, the nozzle of receptacle 39 and theband are made wide enough to form the metal film in the proper shape,depending on the finished metal product desired. Furthermore, the rolls52 and 53 will pull the formed strip, sheet or shape at a rate of speeddepending on the amount of molten metal fed by the receptacle nozzle.The undercooled atomized particles can be thrown against the surface 'ofa strip of metal and form a coating, or they can be collected asgranulated or powdered metal particles if a long funnel is substitutedin place of the mold 41.

Fig. 11 shows a construction in which two band atomizers 42' arearranged to spray a metal product 5| which is made up of two layers, andto form such product in a continuous length. Suitable covers 4'! keepthe metal films free from contact with air and a vacuum can be createdif desired, or some other gas can be forced into the space to preventoxidation of or to induce desired chemical reactions with the moltenmetal used. The different metals are positioned in the receptacles 39'placed over the bands.

In Fig. 12 the parts of the machine, not shown, are understood to be thesame as in Fig. 11. The band atomizer has a cover 41 to eliminatecontact with air, and, as in Fig. 2, a tube such as that numbered I9 canbe used to connect the space under the cover 41 to a vacuum pump or tointroduce a supply of neutral gas into the active space under suchcover. The two undercooling and atomizing bands 42' simultaneously formthe atomized metal into a coating on both surfaces of a strip or sheetmetal plate 52' which is drawn by bands 42'. The thickness of thecoating is regulated by the flow of the metal from the receptacle nozzleand by the speed at which the strip or sheet is pulled by the bands 42'.This coating, being made of particles impacted under high velocity andfree of oxidation, will form, on the clean surface of the sheet orstrip,

a more adhering coating than by dipping the sheet in molten metal. Thiscoating has distinctly new characteristics and a new structure andincreased resistance to rust and corrosion on account of the fact thatit is formed of atomized undercooled particles strongly bonded togetherunder impact and further bonded to the metallic surface of the sheet orstrip by pressure of rolls 53'. a

No claim is made herein either to the apparatus or to the productproduced, such respectively constituting the subject matter of mycopending applications Serial No. 33,157 filed July 25, 1935, and SerialNo. 206,396 filed May 6, 1938.

I claim as my invention:

1. A method of producing a metal product from molten metal, whichincludes the steps of producing a flow of molten metal in the form of acontinuous stream, converting such fiow into a stream of film-likeproportions, substantially abstracting the latent heat of all such metalas it moves in such film-like stream, and then subjecting the metal socooled to a forming force while it exists at a temperature slightlybelow t freezing point of such -metal.

2. A method of producing a metal product from molten metal, whichcomprises producing a flow of molten metal in the form of a continuousconsolidated stream, converting such flow into a stream of film-likeproportions, supporting such film-like stream and simultaneouslyabstracting substantially all the latent heat from all the metal in suchstream, projecting the metal so cooled in the form of a .mass ofseparate particiesand subjecting each such particle to a forming forcewhile it exists at a temperature slightlybelow the freezing point and isplastic.

3. A method of producing a metal product, which comprises establishing aflow of molten metal infthe form of a continuous consolidated stream,converting such fiow into a film-like stream moving at a high velocity,uniformly cooling all the metal of such film-like stream andsubstantially abstracting the latent heat therefrom, then subjecting themetal so cooled to forming force while it is plastic and exists at atemperature slightly below its freezing point.

4. A method of producing a metal product,

which comprises establishing a flow of molten metal in the form .of acontinuous consolidated stream, converting such flow into a film-like abatch of molten metal which includes the steps of establishing a fiow ofsuch metal from such batch in the form of a continuous stream,converting such stream of molten metal into a continuous stream offilm-like proportions moving at a high velocity, substantiallydissipating the latent heat of such metal while moving at such highvelocity by subjecting such film-like stream to a cooling medium, and insubjecting the thus partially cooled metal to forming force while it"exists at a temperature slightly below the melting point thereof.

6. A method of producing a metal product from a batch of molten metalwhich includes the steps of establishing a flow from such batch in theform or a continuous stream, converting such flow into a rapidly movingcontinuous stream of film-like proportions while supporting the samesubstantially extracting the latent heat from all the metal as it movesin such film-like stream, breaking the partially cooled stream of metalinto a mass of separate particles while projecting each such particle ata high velocity, and consolidating such particles by impact while eachsuch projected particle exists at a temperature slightly below thefreezing temperature of such metal.

'7. A method of producing a metal product from molten metal, whichincludes the steps of establishing a continuous flow of molten metalfrom a batch of such metal, converting such ilow into a continuousstream of film-like proportions, moving in a straight line, continuingthe straight line motion of such film-like flow while supporting thesame and'while substantially dissipating the latent heat of all themetal constituting such stream, breaking the flow into a mass ofseparate particles of metal projected at a high velocity into a moldwhile existing at a temperature slightly below that of the freezingtemperature of such metal, and subjecting each such particle to impactforce while at, such temperature.

8. A method of producing a metal product from molten metal, whichincludes the steps of establishing a flow of such metal in the form of afilm-like continuous stream moving in a planedefining direction,supporting such film-like stream during a substantial portion of itsmotion and while substantially withdrawing the latent heat of all themetal constituting such stream, then causing such metal to move whileunsupported in the direction of its supported travel and while existingat a temperature substantially that of the freezing point of such metal,and subjecting the metal while slightly below such temperature to aforming force.

9. A method of forming a bi-metal product, which consists inestablishing a fiow of molten metal in the form of a film-likecontinuous stream, supporting such stream while extracting substantiallyall of the latent heat of the metal constituting the same, breaking thestream into a mass of separate metal particles projected at a highvelocity along the line of travel of' such stream and while each suchparticle exists at a temperature substantially equal to that of thefreezing temperature of such metal, subjecting each such particle to animpact force while existing at a temperature slightly below the meltingtemperature of such metal, continuing such stream-like now withoutinterruption thereof from a batch of different molten metal, convertingsuch flow into a stream-like film constituting a continuation of theaforesaid film and while supporting the same and extractingsubstantially all of the latent heat of the metal constituting suchfilm, breaking such fiow into a mass of metal particles existing at atemperature substantially equal to that of the freezing point of suchlast mentioned metal and causing the particles so projected to impactupon previously projected metal while the same exist at a temperatureslightly below the freezing point of the last mentioned metal. q

l0. Amethod of producing a metal product as set forth in claim 2 whereinthe metal from which the product is made is protected against oxidationfrom the time it leaves the molten batch until the metal product isfully formed.

JOSEPH M. MERLE.

CERTIFICATE-OF CORRECTION.

Patent Noo 2,129,702, September 15, 1958.

JOSEPH M. MERLE.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 5,second column, line 16 for "grates read gates; page 5, second column,line L5,

before, "the" second occurrence, insert all; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 15th day of November, A. D; l958.'

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

